1. Field of the Invention
The present invention is concerned with processes for separately removing the embryo and scutellum fractions from whole wheat as an adjunct to the milling process, so as to give substantial increases in wheat germ production, while at the same time yielding finished flour having only minimal, high oil content germ fractions therein, so that the flour exhibits enhanced storability. More particularly, it is concerned with such processes (and the resultant products) wherein tempering and mechanical treatment of the starting wheat are carefully controlled in order to maximize embryo and scutellum separation, making use of conventional equipment typically found in flour mills.
2. Description of the Prior Art
The wheat germ fraction of whole wheat is a unique source of highly concentrated nutrients. It offers much higher protein of high biological value, fat, sugar and mineral content when compared to flour derived from endosperm. Wheat germ is the richest source known of tocopherols (Vitamin E) of plant origin and is also a rich source of thiamine, riboflavin, and niacin. The presence of a large amount of fat and sugar makes wheat germ highly palatable.
Being highly nutritive and palatable, wheat germ is an excellent source of protein and vitamins for fortification of food products. The oil obtained from germ has been a good source of material for production of vitamins in medication and cosmetic industry. Wheat germ therefore commands a premium price in the marketplace.
However, if wheat germ is left in flour, it can adversely affect flour and particularly the storage quality thereof. The highly unsaturated germ oil and rich oxidative and hydrolytic enzymes can initiate and accelerate reactions resulting in increase of acidity and oxidative rancidity. Accordingly, the efficient separation of wheat germ from whole wheat represents a significant commercial factor.
The product referred to as "wheat germ" in the milling industry is actually the embryo constituent of the wheat germ organ, whereas in reality (and as used in botanical science) wheat germ is defined as both the embryo and scutellum fractions of the wheat kernel. This difference in semantics largely stems from the fact that millers have been unable to efficiently remove scutellum from wheat, this fraction normally being carried over with the bran. Economically, wheat scutellum would be even more valuable than the embryo fraction, because scutellum is higher in vitamin and total fat content than embryo. In any event, current technology of germ separation gives yields of about 0.4- 0.5 percent by weight of embryonic germ.
An extensive review of current techniques of germ separation is found in "The Technology of Wheat Germ Separation in Flour Mills", Association of Operative Millers--Bulletin, published in October, 1985. One conventional method is to separate embryonic germ in the break system, in the form of intact germ, by specially designed "germ separator." This requires a large investment in sophisticated equipment and high operational costs. In another method, middlings containing germ particles are passed through a pair of smooth rolls where germ is flatened and separated by sifting. A major disadvantage of this method is that germ oil can be expressed out of the germ particles and transferred to the final flour, which causes loss of valuable germ oil and contamination of the flour.
Accordingly, there is a real and unsatisfied need in the art for a method of efficient embryo separation so as to increase germ yields and minimize flour contamination. In like manner, a method of scutellum separation would represent a significant advance in the art, inasmuch as this would further enhance germ yields and/or give a new, commercially attractive byproduct for the miller. Obviously, if these two goals could be achieved in a simple, stepwise operation as an adjunct to conventional milling processes and without the requirement of sophisticated equipment, the economic benefit to the milling industry would be considerable.